The Tcpdump Group git mirrors - libpcap/blob - pcap-int.h

   1 /*
   2  * Copyright (c) 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the Computer Systems
  16  *      Engineering Group at Lawrence Berkeley Laboratory.
  17  * 4. Neither the name of the University nor of the Laboratory may be used
  18  *    to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef pcap_int_h
  35 #define pcap_int_h
  36
  37 #include <pcap/pcap.h>
  38
  39 #ifdef __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 #if defined(_WIN32)
  44   /*
  45    * Make sure Packet32.h doesn't define BPF structures that we've
  46    * probably already defined as a result of including <pcap/pcap.h>.
  47    */
  48   #define BPF_MAJOR_VERSION
  49   #include <Packet32.h>
  50 #elif defined(MSDOS)
  51   #include <fcntl.h>
  52   #include <io.h>
  53 #endif
  54
  55 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
  56
  57 /*
  58  * Swap byte ordering of unsigned long long timestamp on a big endian
  59  * machine.
  60  */
  61 #define SWAPLL(ull)  ((ull & 0xff00000000000000) >> 56) | \
  62                       ((ull & 0x00ff000000000000) >> 40) | \
  63                       ((ull & 0x0000ff0000000000) >> 24) | \
  64                       ((ull & 0x000000ff00000000) >> 8)  | \
  65                       ((ull & 0x00000000ff000000) << 8)  | \
  66                       ((ull & 0x0000000000ff0000) << 24) | \
  67                       ((ull & 0x000000000000ff00) << 40) | \
  68                       ((ull & 0x00000000000000ff) << 56)
  69
  70 #else /* A recent Visual studio compiler or not VC */
  71
  72 /*
  73  * Swap byte ordering of unsigned long long timestamp on a big endian
  74  * machine.
  75  */
  76 #define SWAPLL(ull)  ((ull & 0xff00000000000000ULL) >> 56) | \
  77                       ((ull & 0x00ff000000000000ULL) >> 40) | \
  78                       ((ull & 0x0000ff0000000000ULL) >> 24) | \
  79                       ((ull & 0x000000ff00000000ULL) >> 8)  | \
  80                       ((ull & 0x00000000ff000000ULL) << 8)  | \
  81                       ((ull & 0x0000000000ff0000ULL) << 24) | \
  82                       ((ull & 0x000000000000ff00ULL) << 40) | \
  83                       ((ull & 0x00000000000000ffULL) << 56)
  84
  85 #endif /* _MSC_VER */
  86
  87 /*
  88  * Maximum snapshot length.
  89  *
  90  * Somewhat arbitrary, but chosen to be:
  91  *
  92  *    1) big enough for maximum-size Linux loopback packets (65549)
  93  *       and some USB packets captured with USBPcap:
  94  *
  95  *           http://desowin.org/usbpcap/
  96  *
  97  *       (> 131072, < 262144)
  98  *
  99  * and
 100  *
 101  *    2) small enough not to cause attempts to allocate huge amounts of
 102  *       memory; some applications might use the snapshot length in a
 103  *       savefile header to control the size of the buffer they allocate,
 104  *       so a size of, say, 2^31-1 might not work well.
 105  *
 106  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
 107  */
 108 #define MAXIMUM_SNAPLEN         262144
 109
 110 struct pcap_opt {
 111         char    *device;
 112         int     timeout;        /* timeout for buffering */
 113         u_int   buffer_size;
 114         int     promisc;
 115         int     rfmon;          /* monitor mode */
 116         int     immediate;      /* immediate mode - deliver packets as soon as they arrive */
 117         int     nonblock;       /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */
 118         int     tstamp_type;
 119         int     tstamp_precision;
 120 };
 121
 122 typedef int     (*activate_op_t)(pcap_t *);
 123 typedef int     (*can_set_rfmon_op_t)(pcap_t *);
 124 typedef int     (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
 125 typedef int     (*inject_op_t)(pcap_t *, const void *, size_t);
 126 typedef void    (*save_current_filter_op_t)(pcap_t *, const char *);
 127 typedef int     (*setfilter_op_t)(pcap_t *, struct bpf_program *);
 128 typedef int     (*setdirection_op_t)(pcap_t *, pcap_direction_t);
 129 typedef int     (*set_datalink_op_t)(pcap_t *, int);
 130 typedef int     (*getnonblock_op_t)(pcap_t *);
 131 typedef int     (*setnonblock_op_t)(pcap_t *, int);
 132 typedef int     (*stats_op_t)(pcap_t *, struct pcap_stat *);
 133 #ifdef _WIN32
 134 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
 135 typedef int     (*setbuff_op_t)(pcap_t *, int);
 136 typedef int     (*setmode_op_t)(pcap_t *, int);
 137 typedef int     (*setmintocopy_op_t)(pcap_t *, int);
 138 typedef HANDLE  (*getevent_op_t)(pcap_t *);
 139 typedef int     (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
 140 typedef int     (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
 141 typedef u_int   (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
 142 typedef int     (*setuserbuffer_op_t)(pcap_t *, int);
 143 typedef int     (*live_dump_op_t)(pcap_t *, char *, int, int);
 144 typedef int     (*live_dump_ended_op_t)(pcap_t *, int);
 145 typedef PAirpcapHandle  (*get_airpcap_handle_op_t)(pcap_t *);
 146 #endif
 147 typedef void    (*cleanup_op_t)(pcap_t *);
 148
 149 /*
 150  * We put all the stuff used in the read code path at the beginning,
 151  * to try to keep it together in the same cache line or lines.
 152  */
 153 struct pcap {
 154         /*
 155          * Method to call to read packets on a live capture.
 156          */
 157         read_op_t read_op;
 158
 159         /*
 160          * Method to call to read packets from a savefile.
 161          */
 162         int (*next_packet_op)(pcap_t *, struct pcap_pkthdr *, u_char **);
 163
 164 #ifdef _WIN32
 165         ADAPTER *adapter;
 166 #else
 167         int fd;
 168         int selectable_fd;
 169 #endif /* _WIN32 */
 170
 171         /*
 172          * Read buffer.
 173          */
 174         u_int bufsize;
 175         void *buffer;
 176         u_char *bp;
 177         int cc;
 178
 179         int break_loop;         /* flag set to force break from packet-reading loop */
 180
 181         void *priv;             /* private data for methods */
 182
 183 #ifdef HAVE_REMOTE
 184         struct pcap_samp rmt_samp;      /* parameters related to the sampling process. */
 185 #endif
 186
 187         int swapped;
 188         FILE *rfile;            /* null if live capture, non-null if savefile */
 189         u_int fddipad;
 190         struct pcap *next;      /* list of open pcaps that need stuff cleared on close */
 191
 192         /*
 193          * File version number; meaningful only for a savefile, but we
 194          * keep it here so that apps that (mistakenly) ask for the
 195          * version numbers will get the same zero values that they
 196          * always did.
 197          */
 198         int version_major;
 199         int version_minor;
 200
 201         int snapshot;
 202         int linktype;           /* Network linktype */
 203         int linktype_ext;       /* Extended information stored in the linktype field of a file */
 204         int tzoff;              /* timezone offset */
 205         int offset;             /* offset for proper alignment */
 206         int activated;          /* true if the capture is really started */
 207         int oldstyle;           /* if we're opening with pcap_open_live() */
 208
 209         struct pcap_opt opt;
 210
 211         /*
 212          * Place holder for pcap_next().
 213          */
 214         u_char *pkt;
 215
 216 #ifdef _WIN32
 217         struct pcap_stat stat;          /* used for pcap_stats_ex() */
 218 #endif
 219
 220         /* We're accepting only packets in this direction/these directions. */
 221         pcap_direction_t direction;
 222
 223         /*
 224          * Flags to affect BPF code generation.
 225          */
 226         int bpf_codegen_flags;
 227
 228         /*
 229          * Placeholder for filter code if bpf not in kernel.
 230          */
 231         struct bpf_program fcode;
 232
 233         char errbuf[PCAP_ERRBUF_SIZE + 1];
 234         int dlt_count;
 235         u_int *dlt_list;
 236         int tstamp_type_count;
 237         u_int *tstamp_type_list;
 238         int tstamp_precision_count;
 239         u_int *tstamp_precision_list;
 240
 241         struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */
 242
 243         /*
 244          * More methods.
 245          */
 246         activate_op_t activate_op;
 247         can_set_rfmon_op_t can_set_rfmon_op;
 248         inject_op_t inject_op;
 249         save_current_filter_op_t save_current_filter_op;
 250         setfilter_op_t setfilter_op;
 251         setdirection_op_t setdirection_op;
 252         set_datalink_op_t set_datalink_op;
 253         getnonblock_op_t getnonblock_op;
 254         setnonblock_op_t setnonblock_op;
 255         stats_op_t stats_op;
 256
 257         /*
 258          * Routine to use as callback for pcap_next()/pcap_next_ex().
 259          */
 260         pcap_handler oneshot_callback;
 261
 262 #ifdef _WIN32
 263         /*
 264          * These are, at least currently, specific to the Win32 NPF
 265          * driver.
 266          */
 267         stats_ex_op_t stats_ex_op;
 268         setbuff_op_t setbuff_op;
 269         setmode_op_t setmode_op;
 270         setmintocopy_op_t setmintocopy_op;
 271         getevent_op_t getevent_op;
 272         oid_get_request_op_t oid_get_request_op;
 273         oid_set_request_op_t oid_set_request_op;
 274         sendqueue_transmit_op_t sendqueue_transmit_op;
 275         setuserbuffer_op_t setuserbuffer_op;
 276         live_dump_op_t live_dump_op;
 277         live_dump_ended_op_t live_dump_ended_op;
 278         get_airpcap_handle_op_t get_airpcap_handle_op;
 279 #endif
 280         cleanup_op_t cleanup_op;
 281 };
 282
 283 /*
 284  * BPF code generation flags.
 285  */
 286 #define BPF_SPECIAL_VLAN_HANDLING       0x00000001      /* special VLAN handling for Linux */
 287
 288 /*
 289  * This is a timeval as stored in a savefile.
 290  * It has to use the same types everywhere, independent of the actual
 291  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
 292  * platforms and 64-bit tv_sec values on other platforms, and writing
 293  * out native `struct timeval' values would mean files could only be
 294  * read on systems with the same tv_sec size as the system on which
 295  * the file was written.
 296  */
 297
 298 struct pcap_timeval {
 299     bpf_int32 tv_sec;           /* seconds */
 300     bpf_int32 tv_usec;          /* microseconds */
 301 };
 302
 303 /*
 304  * This is a `pcap_pkthdr' as actually stored in a savefile.
 305  *
 306  * Do not change the format of this structure, in any way (this includes
 307  * changes that only affect the length of fields in this structure),
 308  * and do not make the time stamp anything other than seconds and
 309  * microseconds (e.g., seconds and nanoseconds).  Instead:
 310  *
 311  *      introduce a new structure for the new format;
 312  *
 313  *      send mail to "tcpdump-workers@lists.tcpdump.org", requesting
 314  *      a new magic number for your new capture file format, and, when
 315  *      you get the new magic number, put it in "savefile.c";
 316  *
 317  *      use that magic number for save files with the changed record
 318  *      header;
 319  *
 320  *      make the code in "savefile.c" capable of reading files with
 321  *      the old record header as well as files with the new record header
 322  *      (using the magic number to determine the header format).
 323  *
 324  * Then supply the changes by forking the branch at
 325  *
 326  *      https://github.com/the-tcpdump-group/libpcap/issues
 327  *
 328  * and issuing a pull request, so that future versions of libpcap and
 329  * programs that use it (such as tcpdump) will be able to read your new
 330  * capture file format.
 331  */
 332
 333 struct pcap_sf_pkthdr {
 334     struct pcap_timeval ts;     /* time stamp */
 335     bpf_u_int32 caplen;         /* length of portion present */
 336     bpf_u_int32 len;            /* length this packet (off wire) */
 337 };
 338
 339 /*
 340  * How a `pcap_pkthdr' is actually stored in savefiles written
 341  * by some patched versions of libpcap (e.g. the ones in Red
 342  * Hat Linux 6.1 and 6.2).
 343  *
 344  * Do not change the format of this structure, in any way (this includes
 345  * changes that only affect the length of fields in this structure).
 346  * Instead, introduce a new structure, as per the above.
 347  */
 348
 349 struct pcap_sf_patched_pkthdr {
 350     struct pcap_timeval ts;     /* time stamp */
 351     bpf_u_int32 caplen;         /* length of portion present */
 352     bpf_u_int32 len;            /* length this packet (off wire) */
 353     int         index;
 354     unsigned short protocol;
 355     unsigned char pkt_type;
 356 };
 357
 358 /*
 359  * User data structure for the one-shot callback used for pcap_next()
 360  * and pcap_next_ex().
 361  */
 362 struct oneshot_userdata {
 363         struct pcap_pkthdr *hdr;
 364         const u_char **pkt;
 365         pcap_t *pd;
 366 };
 367
 368 #ifndef min
 369 #define min(a, b) ((a) > (b) ? (b) : (a))
 370 #endif
 371
 372 int     pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
 373
 374 #include <stdarg.h>
 375
 376 #include "portability.h"
 377
 378 /*
 379  * Does the packet count argument to a module's read routine say
 380  * "supply packets until you run out of packets"?
 381  */
 382 #define PACKET_COUNT_IS_UNLIMITED(count)        ((count) <= 0)
 383
 384 /*
 385  * Routines that most pcap implementations can use for non-blocking mode.
 386  */
 387 #if !defined(_WIN32) && !defined(MSDOS)
 388 int     pcap_getnonblock_fd(pcap_t *);
 389 int     pcap_setnonblock_fd(pcap_t *p, int);
 390 #endif
 391
 392 /*
 393  * Internal interfaces for "pcap_lib_version()".
 394  *
 395  * "pcap_platform_lib_version()" returns platform-specific version
 396  * information, or NULL if there isn't any.
 397  */
 398 const char *pcap_platform_lib_version(void);
 399
 400 /*
 401  * Internal interfaces for "pcap_create()".
 402  *
 403  * "pcap_create_interface()" is the routine to do a pcap_create on
 404  * a regular network interface.  There are multiple implementations
 405  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
 406  * with the one used chosen by the configure script.
 407  *
 408  * "pcap_create_common()" allocates and fills in a pcap_t, for use
 409  * by pcap_create routines.
 410  */
 411 pcap_t  *pcap_create_interface(const char *, char *);
 412 pcap_t  *pcap_create_common(char *, size_t);
 413 int     pcap_do_addexit(pcap_t *);
 414 void    pcap_add_to_pcaps_to_close(pcap_t *);
 415 void    pcap_remove_from_pcaps_to_close(pcap_t *);
 416 void    pcap_cleanup_live_common(pcap_t *);
 417 int     pcap_check_activated(pcap_t *);
 418
 419 /*
 420  * Internal interfaces for "pcap_findalldevs()".
 421  *
 422  * A pcap_if_list_t * is a reference to a list of devices.
 423  *
 424  * "pcap_platform_finddevs()" is the platform-dependent routine to
 425  * find local network interfaces.
 426  *
 427  * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
 428  * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
 429  *
 430  * "add_dev()" adds an entry to a pcap_if_list_t.
 431  *
 432  * "find_dev()" tries to find a device, by name, in a pcap_if_list_t.
 433  *
 434  * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t
 435  * and, if not, adds an entry for it.
 436  */
 437 struct pcap_if_list;
 438 typedef struct pcap_if_list pcap_if_list_t;
 439 int     pcap_platform_finddevs(pcap_if_list_t *, char *);
 440 #if !defined(_WIN32) && !defined(MSDOS)
 441 int     pcap_findalldevs_interfaces(pcap_if_list_t *, char *,
 442             int (*)(const char *));
 443 #endif
 444 pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32,
 445             const char *, char *);
 446 pcap_if_t *find_dev(pcap_if_list_t *, const char *);
 447 pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *,
 448             char *);
 449 int     add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
 450             struct sockaddr *, size_t, struct sockaddr *, size_t,
 451             struct sockaddr *dstaddr, size_t, char *errbuf);
 452 #ifndef _WIN32
 453 pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32,
 454             char *);
 455 int     add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32,
 456             struct sockaddr *, size_t, struct sockaddr *, size_t,
 457             struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
 458 #endif
 459
 460 /*
 461  * Internal interfaces for "pcap_open_offline()".
 462  *
 463  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
 464  * by pcap_open_offline routines.
 465  *
 466  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
 467  * appropriate, and frees all data common to all modules for handling
 468  * savefile types.
 469  */
 470 pcap_t  *pcap_open_offline_common(char *ebuf, size_t size);
 471 void    sf_cleanup(pcap_t *p);
 472
 473 /*
 474  * Internal interfaces for both "pcap_create()" and routines that
 475  * open savefiles.
 476  *
 477  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
 478  * and "pcap_next_ex()".
 479  */
 480 void    pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
 481
 482 #ifdef _WIN32
 483 void    pcap_win32_err_to_str(DWORD, char *);
 484 #endif
 485
 486 int     install_bpf_program(pcap_t *, struct bpf_program *);
 487
 488 int     pcap_strcasecmp(const char *, const char *);
 489
 490 #ifdef __cplusplus
 491 }
 492 #endif
 493
 494 #endif